Changeset 14392 for branches/PushGP/HeuristicLab.Algorithms.PushGP/HeuristicLab.Algorithms.PushGP/Generators/CodeGenerator.cs

Timestamp:

11/15/16 21:10:17 (8 years ago)

Author:

pkimmesw

Message:

#2665 Full Push 3.0 instruction set and tests; Added first benchmark test (count odds) for random walk tests;

File:

• branches/PushGP/HeuristicLab.Algorithms.PushGP/HeuristicLab.Algorithms.PushGP/Generators/CodeGenerator.cs (modified) (2 diffs)

branches/PushGP/HeuristicLab.Algorithms.PushGP/HeuristicLab.Algorithms.PushGP/Generators/CodeGenerator.cs

@@ -1 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using HeuristicLab.Algorithms.PushGP.Expressions;
+using HeuristicLab.Algorithms.PushGP.Interpreter;
+using HeuristicLab.Core;
 using HeuristicLab.Random;
 
 namespace HeuristicLab.Algorithms.PushGP.Generators
 {
-    public static class CodeGenerator
+    /// <summary>
+    /// The following is the standard Push random code generation algorithm, which is used for the CODE.RAND instruction.
+    /// It may also be useful for the initialization of programs in evolutionary computation systems, and it is used for this purpose in PushGP.
+    /// It produces a uniform distribution of sizes and what seems to be a reasonable distribution of shapes, in a reasonable amount of time.
+    /// </summary>
+    /// <see cref="http://faculty.hampshire.edu/lspector/push3-description.html#RandomCode"/>
+    public class CodeGenerator
     {
-        private static FastRandom random = new FastRandom();
-        public static IEnumerable<Expression> RandomCode(int maxPoints)
+        private static IRandom random = new FastRandom();
+        private readonly IInterpreter interpreter;
+
+        public CodeGenerator(IInterpreter interpreter)
         {
-            var actualPoints = random.Next(1, maxPoints);
-
-            return RandomCodeWithSize(actualPoints).ToArray();
+            this.interpreter = interpreter;
         }
 
-        private static IEnumerable<Expression> RandomCodeWithSize(int points)
+        /// <summary>
+        /// Generates a random program with a given max size
+        /// </summary>
+        /// <param name="maxPoints"></param>
+        /// <returns>Returns an ExpandExpression if maxPoints smaller or equal to Configuration.MaxProgramPoints and Noop otherwise</returns>
+        public Expression RandomProgram(int maxPoints)
+        {
+            return ExecExpandExpression.TryCreate(interpreter.CodeGenerator.RandomCode(maxPoints).ToArray(), interpreter.Configuration);
+        }
+
+        public IEnumerable<Expression> RandomCode(int maxPoints)
+        {
+            var actualPoints = random.Next(1, Math.Max(1, maxPoints));
+
+            return RandomCodeWithSize(actualPoints);
+        }
+
+        private IEnumerable<Expression> RandomCodeWithSize(int points)
         {
             if (points == 1)
             {
-                // TODO: If this is an "ephemeral random constant"???? then return a randomly - chosen value of the appropriate type;
-                var opCode = (OpCode)random.Next(OpCodeExtensions.Min, OpCodeExtensions.Max);
-
-                return new[] { ExpressionFactory.Create(opCode) };
+                var index = random.Next(0, ExpressionTable.Count + this.interpreter.CustomExpressions.Count - 2);
+                return new[] { this.CreateExpression(index) };
             }
             else
             {
                 var sizesThisLevel = Decompose(points - 1, points - 1);
-
                 return sizesThisLevel.SelectMany(size => RandomCodeWithSize(size)).Shuffle(random);
             }
         }
 
-        private static IEnumerable<int> Decompose(int number, int maxParts)
+        private IEnumerable<int> Decompose(int number, int maxParts)
         {
             if (number == 1 || maxParts == 1)
@@ -42 +65 @@
             {
                 var thisPart = random.Next(1, number - 1);
-
                 return new[] { thisPart }.Concat(Decompose(number - thisPart, maxParts - 1));
             }
         }
+
+        private Expression CreateExpression(int index)
+        {
+            return (index >= 0 && index < ExpressionTable.Count)
+                ? ExpressionTable.GetExpression(index)
+                : new NameDefineXExecExpression(this.interpreter.CustomExpressions.ElementAt(index - (ExpressionTable.Count - 1)).Key);
+        }
     }
 }